Carriage-bow slat



(No Model.)

JOSIAH W. & JOHN W. SHERWOOD.

CARRIAGE BOW SLAT. No. 328,526. Patented Oct. 20, 1885.

WITNESSES: INVENTORS NITED STATES ATENT rrrcn.

JOSIAH NV. SHERWOOD AND JOHN WV. SHERWOOD, OF GRAND RAPIDS, MICHIGAN.

CARRIAGE-BOW SLAT.

SPECIFICATION forming part of Letters Patent No. 328,526, dated October 20, 1885.

Application filed January 3, 1885. Serial No. 151,952. (No model.)

To all whom it may concern:

Be it known that we, J OSIAH W. SHER- woon and JOHN W. SHERWOOD, both of Grand Rapids, in the county of Kent and State of Michigan, have invented a new and useful Improvement in Carriage-Bow Slats, of which the following is a specification.

The invention relates to improvements in the construction of carriage-bow slats or sockets composed wholly or in part of thin veneers of Wood in concentric layers. Heretofore such slats have been constructed with a central core of wood having the slat-iron attached to one end and a metal tube or socket at the other, and covered with layers of thin veneer, consisting of a single piece Wrapped around said core and secured with glue. This method is objectionable because,the veneer consisting of but one piece, the fibers of all the layers are practically parallel, and therefore easily split. It is also very difficult to obtain good adhesion of either the veneer to the outer or the tenon on the end of the bow to the inner surface of the said metal socket. The inner core and V metal socket add materially to the weight and cost of the article when complete.

It has been attempted to make slats wholly of veneer in tubular form, having the slat-iron cemented thereto; but they have proved too weak to be efficient and durable. The veneer used has been a single piece wrapped concentrically to form several thicknesses. Therefore, although on account of the taper of the slat the fibers on the different layers of veneer crossed one another slightly at a very obtuse angle, still they were so near parallel that their crossing did not add materially to the strength of the slat.

Where slats are made wholly of veneer in tubular form, it is necessary that the material be arranged with respect to its grain, so as to give both transverse stiffness or resistance to bending and longitudinal stiffness, whereby it may maintain its tubular form and resist crushing and splitting. The first is maintained by laying the grain of the veneer parallel with what is to be the longitudinal dimension of the slat; the second by laying the grain around the slat in planes transverse thereto to encircle it. The best results are therefore to be attained by combining the two methods, which necessitates the use of two or more independent veneers. These may be arranged alternately in the two ways last above mentioned; but as it is merely necessary, in order to form a-surrounding band which shall prevent the splitting or crushing of the slat, that the grain of one or more veneers shall have a general circumferential direction, we prefer to roll the independent veneers spirally, but in opposite directions, taking care that the pitch of the spiral shall be such as to permit the slat to be encircled by continuous fibers of the veneer. The bow and slat iron may then be applied to the slat in any known or preferred manner. We are thus able to produce a slat in which is obviated the principal weakness of the slats heretofore madeviz., the liability to be crushed or split by the bow or slat iron, caused by laying all of the fibers of the veneer substantially lengthwise of the slat.

In the accompanying drawings we have shown a method of carrying our invention into effect.

Figure 1 is a broken portion of a core and two veneers arranged to produce the spiral structure. Fig. 2is a section of the small end of a slat, showing the manner of attaching a slat-iron to the same. Fig. 3 is a section showing the layers of veneer in detail and the tenon on the end of the bow.

Similar letters indicate like parts in all the figures.

A and B represent thin veneers of suitable wood attached to and wrapped around the cone 0, and cut with the grain running diagonally in opposite directions, thus forming alternate spiral layers of fiber,which are firmly secured to each other with glue, thus making a very strong structure, as each layer has a tendency to prevent the next from splitting.

In case the core is omitted the resulting tube is not easily crushed, as in so doing the timber would be broken instead of merely split, as in case the fibers were parallel with the axis of the tube and with each other.

The veneers A and B may be secured to the core 0, thus constituting an improved solid slat; or the said core can be so arranged as to be finally removed, thus forming no part of the finished work, which latter method'we prefer.

One of said veneers may be placed with its grain or fibers parallel with the axis of the core and the other at right angles with the same, as at A B, Fig. 3; or the grain'of each I veneer may have any angle with said axis that occasion may require, provided that the structure is encircled by continuous fibers of one or more layers of veneer, to form a containing-band.

The slat-iron D is secured to the slat by means of any suitable cement, E, preferably of glue and sawdust, atemporary core being inserted in the cavity F while placing the iron and cement in position.

G is the ordinary carriage-bow, having a tenon, H, to fit the cavity F and secured in place by glue.

We are aware that tubes have been made of several layers of veneer, the fibers of one of the layers being laid oircumferentially of the tube to encircle it. We are also aware that a single veneer with the grain arranged length wise of the slat, and not encircling the same, and secured to a core, is used-in making carriage-bow slats or'sockets. WVe do'not claim these features, broadly.

What we claim and wish to secure is as follows:

. 1. In a carriage-bow slat,..the combination, with the'slatiron, ofjtwo or more separate and independent pieces of veneer,one of which is arranged with its grain running circumferentially of the slat, so that the latter is encircled by continuous fibers, and the splitting of the slat by the 'slatiron prevented, substantially as set forth.

2. In a carriage-bow slat, the combination, with the slat-iron,of two or more separate and independent pieces of veneer arranged with their grain running spirally in opposite directions, substantially as set forth.

3. In a carriage-bow slat, the combination, with the slat-iron, of the core (3 and a covering-veneer having its grain running around said core, so that the latter is encircled by continuous fibers, substantially assetforth.

4. In acarriage-bow slat, the combination of a tapering tube, a slat-iron havinga circumferentiallyribbed extension inserted in the smaller end of said;tube, and a cement filling of conical form situated in the tapering tube and surroundingsaidribbed extension,

substantially as set forth.

JOSIAH'W.- SHERWOOD. JOHN W. SHERWVOOD.

Witnesses: Y

L. V. MOULTON, GEO. W. SrIooL. 

